PIK3CA and breast carcinoma: Activating mutations of PIK3CA, which encodes for the p110α catalytic subunit of phosphoinositide 3‐kinase (PI3K), are among the most frequent alterations in human breast cancer and lead to an hyperactivated PI3K pathway signalling (Yuan & Cantley, 2008; Zhao & Vogt, 2008; Miller, 2012).